Anastatus (Anastatus) gansuensis Chen & Zang

Chen, Yong-Ming, Gibson, Gary A. P., Peng, Ling-Fei, Iqbal, Asim & Zang, Lian-Sheng, 2019, Anastatus Motschulsky (Hymenoptera, Eupelmidae): egg parasitoids of Caligula japonica Moore (Lepidoptera, Saturniidae) in China, ZooKeys 881, pp. 109-134 : 115-124

Anastatus (Anastatus) gansuensis Chen & Zang sp. nov. Figs 2 A–I , 3 A–G , 4 A–H

Type material.

Holotype ♀ (FAFU), Shanchacun, Yuntai Town, Kangxian County, Gansu Province, China, 01.III.2017, Yong-Ming Chen. Allotype ♂ (FAFU), same data as holotype (from subsequently established colony on A. pernyi ).

Additional paratypes.

Same data as holotype (2♀, 1♂ FAFU). Gansu Province, Kang Co., Longnan City, collected 23.I.2018, Yong-Ming Chen, ex. Caligula japonica Moore egg, lab reared on eggs of Antheraea pernyi ( Guérin-Méneville) (Lep: Saturniidae ) (2♀, 1♂ AICF; 2♀, 1♂ BMNH; 67♀, 18♂ CNC; 5♀, 3♂ FAFU; 6♀ IZCAS; 2♀, 1♂ USNM).

Diagnosis.

Female. Macropterous ( Fig. 2B ); fore wing with broad hyaline cross band behind marginal vein and with apical margin more distinctly angulate (V-like) than basal margin such that length of hyaline band along marginal vein about twice medial length of hyaline band ( Fig. 3A ), and usually with a few isolated dark setae within band medially ( Fig. 3C ). Mesosoma (excluding legs) dark except prepectus and pronotum or at least lateral, vertical surface of pronotum, pale ( Fig. 2A, B, E, F ); procoxa pale, similar in color to lateral surface of pronotum ( Fig. 2F ). Mesoscutum with posterior concave portion setose only medially, width of setose region about equal to width of bare region on either side ( Fig. 2E ). Mesotarsus (excluding tarsal pegs) with at least basal four tarsomeres similarly pale ( Fig. 3C ). Antenna with all funiculars (fl2-fl8) longer than wide ( Fig. 2 G–I ).

Male. Legs with all femora mostly to entirely dark, mesotibia entirely pale, and metatibia mostly dark, pale basally for a distance at most equal to about apical width or about one-quarter length of tibia ( Fig. 4B ). Flagellum ( Fig. 4G ) with clava distinctly shorter than combined length of fl6-fl8, with at least fl6 and fl7 obviously longer than wide ( Fig. 4H ).

Description.

Female (habitus, Fig. 2A, B ). Body length 2.2-3.9 mm.

Color. Head ( Fig. 2C, D ) mostly metallic green to bluish-green but with variably extensive and distinct coppery to reddish-violaceous lusters on at least parascrobal region and interantennal prominence ( Fig. 2C ) and sometimes on frontovertex, including ocellar triangle ( Fig. 2D ). Maxillary and labial palpi dark brown. Antenna with scape mostly pale, yellowish ( Fig. 2G ), except variably extensively darker brown and sometimes with slight metallic luster dorsoapically ( Fig. 2C ); pedicel and flagellum dark brown ( Fig. 2 G–I ).

Pronotum mostly pale ( Fig. 2E, F ) except black posterolaterally anterior each spiracle, and concave, dorsomedial part often variably darker brownish ( Fig. 2A, E ); propleuron similarly pale as lateral surface of pronotum but prosternum dark. Mesonotum ( Fig. 2E ) mostly dark with metallic green to bluish-green lusters similar to head except convex part of mesoscutal medial lobe and/or scutellar-axillar complex anteriorly usually with slight coppery to reddish lusters, and concave posteromedial part of mesoscutum more distinctly blue to purple adjacent to medially dark violaceous to black setose part ( Fig. 2E ). Prepectus similarly pale as lateral surface of pronotum ( Fig. 2F ). Tegula dark brown. Mesopleurosternum mostly dark with greenish luster except variably distinctly paler anterodorsally near prepectus, the paler region at most extending to or slightly beyond level of base of tegula, and strigose medial part of acropleuron usually with slight coppery to reddish-violaceous lusters under some angles of light ( Fig. 2F ). Front leg with coxa, trochanter and trochantellus similarly pale as lateral surface of pronotum and prepectus; femur with anterior and/or dorsal surfaces and tibia with anterior surface similarly pale as coxa, but otherwise variably dark brown; tarsus with at least apical tarsomere brown but basal four tarsomeres pale to variably dark brown. Middle leg with trochanter and trochantellus at least ventrally dark; femur with dorsal surface longitudinally dark at least posteriorly, but ventral surface and usually dorsal surface anteriorly paler, and more whitish-translucent, anteroapically; tibia dark dorsally but paler basally, ventrally, and apically except for dark apical pegs; mesotibial spur and mesotarsus similarly pale, yellowish-white to white, except for dark pegs ( Fig. 3E ). Hind leg with at least ventral surface of trochanter and trochantellus dark; femur with dorsal and ventral surfaces paler than longitudinally dark anterior and posterior surfaces; tibia with dorsal surface dark but paler basally, apically and ventrally; tarsus with at least apical tarsomere brown and often one or two basal tarsomeres variably distinctly brownish. Macropterous, with fore wing extending beyond gastral apex when folded over dorsum ( Fig. 2B ); fore wing ( Fig. 3A ) with basal region mostly hyaline but brownish basally, with dark setae posteriorly along vanal and cubital areas and apically within basal brownish part ( Fig. 3B ), and hyaline part with whitish-translucent setae over at least about posterior half bare but behind length of SMV from level of base of parastigma; discal region ( Fig. 3A ) brownish from base of parastigma to level slightly beyond apex of PMV but hyaline towards wing apex and with complete hyaline cross band behind MV; hyaline cross band with white hair-like setae except for a few isolated dark setae within band medially ( Fig. 3C ), with apical margin reaching base of STV along leading margin and noticeably angulate compared to more evenly curved basal margin such that length of hyaline band along MV is about twice medial length ( Fig. 3A ); brownish region basal to hyaline cross band with slightly lanceolate dark brown setae except often for variably distinct, more orangish region of lanceolate setae behind parastigma and base of MV anterior to medial fold (when apparent, orangish region of setae reaching parastigma and base of MV, but at least narrowly separated by dark brown setae from basal cell basally and hyaline cross vein apically, Fig. 3B ), and with entirely dark setae beyond hyaline cross band, the setae slightly lanceolate behind venation but more hair-like apically within more hyaline part. Metanotum and propodeum ( Fig. 2E ) dark brown or with slight metallic purple luster.

Gaster ( Fig. 3D ) mostly dark but syntergal flange and ovipositor sheaths pale, yellowish; in dorsal view Gt1 brown basally and variably extensively white apically and Gt2 translucent-hyaline so with sub-basal whitish region ( Fig. 3D ), but in lateral view basal two sternites entirely white ( Fig. 2B ); Gt3-Gt5 dark brown or with slight violaceous luster, and Gt6 and syntergum except for flange with green to bluish luster ( Fig. 3D ).

Setation. Head with slightly lanceolate, whitish-translucent setae on lower face, interantennal prominence, lower parascrobal region ( Fig. 2C ) and gena behind eye ( Fig. 2B, D ), and with dark hair-like setae on upper parascrobal region and frontovertex ( Fig. 2D ).

Pronotum mostly bare but with a few long, bristle-like setae in transverse line anterior to spiracle and similar seta medially on either side of mediolongitudinal groove ( Fig. 2E ). Mesonotum ( Fig. 2E ) with convex anteromedial mesoscutal lobe, uniformly, inconspicuously setose with whitish hair-like setae, outer convex surface of lateral lobe laterally with 1-2 rows of somewhat longer whitish setae, and posteromedial concave part of mesoscutum with more conspicuous, very slightly lanceolate white setae medially, the region of white setae about as wide as bare region on either side of band and not extending to line of dark hair-like setae on inner inclined surface of lateral lobe near dorsally carinate posteromedial part of lateral lobe; scutellar-axillar complex bare, except for dark setae laterally on axillae and posterolaterally on scutellum, the posteriormost setae somewhat longer and more bristle-like than others. Mesopleurosternum sparsely setose with whitish-translucent hair-like setae ventrally and more densely, uniformly setose with very slightly lanceolate whitish-translucent setae anterolaterally to level about equal with apex of tegula; acropleuron bare ( Fig. 2F ). Propodeum bare except for a few slightly lanceolate white setae along anterior margin lateral of spiracle and along extreme lateral margin ( Fig. 2E ).

Structure. Head in frontal view ( Fig. 2C ) about 1.3 × wider than high; in dorsal view ( Fig. 2D ) width about 2 × length and about 3.5 × minimum distance between eyes, with vertex gradually curved to occiput without margin or carina; in lateral view about 1.6 × higher than long; eye height about 2 × length of malar space; OOL: LOL: POL: MPOD (holotype) = 3: 6: 11.4: 6.2; scrobal depression ( Fig. 1C ) with abrupt to carinate margins laterally but dorsally margins less distinct and not complete below anterior ocellus, separated medially by short, lighter colored line or vertical ridge below ocellus, with indistinctly delimited dorsal margin separated from anterior ocellus by distance slightly less than longitudinal diameter of ocellus. Antenna (holotype) with relative length (width) of scape = 43(7); pedicel = 10(5); fl1-fl8 = 4(5), 13(6), 15(6), 16(7), 14(7), 14(7.5), 12(8), 11(8); clava 23(9).

Mesoscutum ( Fig. 2E ) slightly wider than long, with anterior, convex part of medial lobe V-shaped with slightly sinuate to slightly outcurved sides convergent posteriorly for about 0.7 × medial length of mesoscutum; lateral lobe carinately margined over almost posterior half; medial length of scutellar-axillar complex, including frenal area, about as long as maximum width with scutellum about 1.25 × as long as own width, Fore wing about 2.7 × as long as maximum width; smv: mv: pmv: stv (holotype) = 51: 70: 33: 10. Propodeum typical of genus, bowtie-like ( Fig. 2E ). Profemur with ventral margin evenly arched, without abrupt angulation or denticle within about apical third, and with 2 or 3 dorsoapical pegs. Mesotibia with apical patch of 3-6 pegs ( Fig. 3E ). Mesotarsus with single row of pegs on either side of basal three tarsomeres and single peg apically on either side of penultimate tarsomere ( Fig. 3E ).

Gaster with ovipositor sheaths at least slightly protruding beyond syntergal flange ( Fig. 3D ), but for distance up to about 2 × length of flange.

Sculpture. Head with vertex and interocellar triangle transversely alutaceous to alutaceous-strigose, upper parascrobal region and frons to posterior ocelli on either side of anterior ocellus more mesh-like coriaceous to coriaceous-imbricate or coriaceous-granular, and lower half of parascrobal region reticulate-rugulose; lower face reticulate to reticulate-rugose; interantennal prominence reticulate-imbricate; scrobal depression mostly reticulate-imbricate.

Mesoscutum with convex anterior part of medial lobe uniformly punctate-reticulate, posteromedial concave part or medial lobe smooth and shiny, and lateral lobes mostly finely mesh-like coriaceous to alutaceous, with sculpture of inner inclined surfaces more distinct lateral of anteromedial lobe and much finer to smooth and shiny posteriorly near scutellar-axillar complex. Scutellar-axillar complex uniformly, similarly punctate-reticulate as convex part of medial lobe. Mesopleurosternum with anterolateral region finely mesh-like coriaceous but dorsally bare part near tegula more alutaceous-coriaceous; acropleuron mostly longitudinally strigose, more minutely centrally, sculpture dorsally and ventrally more longitudinally strigose-coriaceous and posteriorly mesh-like coriaceous with larger cell size.

Gaster ( Fig. 3D ) with Gt1 and Gt2 dorsally almost smooth, only obscurely and very finely mesh-like coriaceous, Gt3-Gt5 more distinctly, somewhat transversely, coriaceous-reticulate with sculpture defined by slightly raised lines, and Gt6 and syntergum more transversely coriaceous-alutaceous to mesh-like coriaceous.

Male (habitus, Fig. 4A, B ). Body length 2.0-2.2 mm.

Color. Head with frontal surface ( Fig. 4C ) mostly green to bluish-green, frontovertex variably extensively dark or with slight coppery to reddish-violaceous lusters ( Fig. 4A, C ). Maxillary and labial palpi dark brown. Antennae with scape mostly yellow, but dorsoapically dark with variably distinct metallic green luster ( Fig. 4G ); pedicel dark except ventral surface usually paler; flagellum uniformly dark such that mps not conspicuous from surrounding cuticle ( Fig. 4G ).

Mesosoma ( Fig. 4A, B, D ) dark with mostly green to bluish-green lusters, though scutellar-axillar complex ( Fig. 4A ) and dorsellum ( Fig. 4E ) dark with coppery to reddish-violaceous lusters similar to frontovertex, propodeum ( Fig. 4E ) more distinctly blue to purple, and mesepisternum posteriorly near metapleuron usually more violaceous ( Fig. 4D ). Front leg with coxa, trochanter and most of femur dark, but following pale: trochantellus, femur apically, tibia except for dark mesotibial apical pegs, and tarsus except pale often apical tarsomere variably darker brown. Middle leg color pattern similar to front leg except femur often somewhat more extensively pale apically or dorsoapically along anterior margin and apical tarsomere more distinctly dark, but mesotibial spur similarly pale as basal four tarsomeres. Hind leg mostly dark but at least ventral surface of trochantellus, tibia basally for distance less than one-third length of tibia, and basal four tarsomeres pale ( Fig. 4B ). Fore wing entirely hyaline with yellowish to yellowish-brown venation and dark, hair-like setae.

Gaster mostly dark brown but with variably distinct metallic green luster dorsobasally on Gt1 ( Fig. 4B ).

Setation. Head with very slightly lanceolate white setae on lower face, interantennal prominence and parascrobal region ventrally, but more hair-like dark setae on parascrobal region dorsally and frontovertex ( Fig. 4C ), and hair-like white setae on gena. Mesonotum with dark hair-like setae ( Fig. 4D ), the setae slightly longer and more bristle-like on scutellum. Fore wing ( Fig. 4F ) cubital cell ventrally with 3-4 rows of setae along entire length and dorsally with line of setae along entire leading margin and at least a partial second row behind first row; basal cell and disk entirely setose except for slender speculum along length of basal fold from parastigma to medial fold, though this variably obscured by setae on ventral surface at least toward parastigma.

Structure. Head in frontal view ( Fig. 4C ) about 1.2 × wider than high, in dorsal view ( Fig. 4A ) about 2.1 × wider than long, and in lateral view ( Fig. 4B ) about 1.8 × higher than long; OOL: LOL: POL: MPOD (allotype) = 1.0: 1.6: 4.0: 1.6. scrobal depression ( Fig. 4C ) shallow, arch-like, with inclined lateral surfaces extending obscurely to anterior ocellus, but flat surface of depression above toruli usually separated from anterior ocellus by pale, yellowish line almost equal in length to longitudinal diameter of ocellus. Antenna ( Fig. 4G ) with scape almost 3 × as long as maximum width; pedicel subglobular, as long as wide; length of pedicel + flagellum about 2.4 × head width; flagellum densely microsetose with numerous rows of densely packed mps ( Fig. 4G ); fl1 strongly discoidal, not evident between scape and fl2; fl2 dorsoventrally flattened so as to be wider than high and in lateral view distinctly curved with ventral surface concave, but subsequent flagellomeres increasingly subcylindrical and straight ( Fig. 4G ); length(width) of fl2-fl8 and clava in lateral view (allotype): 24(10), 17(10), 17(10), 14(10), 14(10), 13(10), 10(10), 44(11) ( Fig. 4G, H ).

Structure of mesosoma and gaster ( Fig. 4 A–D ) typical for the genus. Fore wing ( Fig. 4F ) 2.2 –2.3× as long as wide; SMV: MV: PMV: STV (allotype) = 20: 11: 8.3: 4.7. Protibia with two dorsoapical spicules. Mid leg with spur about as long as basitarsus.

Sculpture. Head with vertex reticulate-rugose to transversely reticulate-strigose; frons and parascrobal regions mesh-like coriaceous to granular, lower face shallowly reticulate to reticulate-imbricate.

Mesoscutum ( Fig. 4A ) with medial lobe usually more coarsely reticulate-rugulose anteriorly, but at least about posterior two-thirds mesh-like reticulate except sculpture variably extensively finer laterally near notauli and sometimes posteriorly near transscutal articulation, and lateral lobe mostly mesh-like coriaceous; scutellar-axillar complex with dorsal surface of axilla variably distinctly reticulate-rugulose, but larger inclined lateral surface obliquely alutaceous-strigose, and scutellum usually at least slightly reticulate anteromedially but more mesh-like coriaceous to coriaceous-imbricate laterally and posteriorly. Propodeum ( Fig. 4E ) with complete medial carina; plical region smooth and shiny or at most with extremely obscure mesh-like coriaceous sculpture.

Distribution.

Anastatus gansuensis (Genbank accession no. MK373759) originally described from China (Gansu Province).

Biology.

Solitary endo-parasitoid of the eggs of C. japonica in the field and, at least in the laboratory, of A. pernyi . Caligula japonica has one generation a year and overwinters in the egg stage; its egg-laying period is from late August to late October in northwestern China ( Qiao et al. 2014). In the winter of 2017 were collected a total 283 egg masses of C. japonica from Gansu Province and reared them in the laboratory (T: 25 ± 1° C, RH: 70 ± 5%, L: D=14h: 10h). Of these, 12 egg masses (4.2%) were parasitized by A. gansuensis . All the emerged wasps of A. gansuensis were females. These were subsequently offered the eggs of A. pernyi in the laboratory as an alternative host for propagation, which led to the discovery that A. gansuensis is thelytokous parthenogenetic. When unmated females were reared on A. pernyi eggs in the laboratory both sexes were produced in a highly female-biased sex ratio (sex ratio about 113:1, ♀:♂ = 5987:53; N =29). There can be 12-14 generations in one year, with one generation completed in 28-33 days under a 25 ± 1° C temperature and 70 ± 5% humidity regime. The average longevity and fecundity of a female (N =29) was 67 (37-93) days and 303 (68-506) eggs, respectively, when fed with honey water (honey: water = 3:7). The results of our rearing experiments indicate that this species has potential as a biological control agent for suppression of C. japonica .

Etymology.

Derived from the name of the province in China from which the type series was originally collected through rearing.

Remarks.

Because of their dark acropleuron, females of A. gansuensis key most closely to females of A. fulloi in Peng et al. (2017), but the two are readily differentiated by the color, setal and structural features as given in the key and diagnoses. Females key to A. tenuipes Bolivar y Pieltain, 1925 in Narendran (2009), in part because the apical margin of the hyaline cross band is angulate and all funiculars are longer than wide in both, but A. tenuipes females are readily differentiated by their pale mesosoma. Similarly, depending on the interpretation of whether or not the scrobal depression "by far" does not reach the anterior ocellus, A. gansuensis females could key to A. tenuipes in Kalina (1981) or to A. splendens Nikol’skaya, 1952 and A. brevicaudus Kalina, 1981. However, in contrast to the key features of Kalina (1981), the mesoscutum is slightly wider than long ( Fig. 2E ), unlike that keyed for A. splendens and the anterior convex portion of the mesoscutal medial lobe is triangular with gradually convergent sides ( Fig. 2E ), unlike that keyed for A. brevicaudus . Furthermore, females of both A. brevicaudus ( Kalina 1981, fig. 14) and A. splendens have at least the apical two funiculars subquadrate to slightly transverse and the acropleuron pale to coppery.

Two features of the fore wing of female A. gansuensis are not apparent in all females: the presence of isolated dark setae within the hyaline cross band medially ( Fig. 3C ) and a region of more orangish setae behind the parastigma and base of the marginal vein anterior to the medial fold ( Fig. 3B ). Although the latter feature is distinctive it is not unique to A. gansuensis , being possessed also by the brachypterous females of A. meilingensis ( Fig. 6E ) and by some females we recognize as A. japonicus , but not by A. fulloi females.

As noted under A. fulloi , a flagellar structure differentiates males of both A. gansuensis and A. meilingensis from those of A. fulloi and A. japonicus . Males of the former two species have the clava distinctly shorter than the combined length of the three apical funiculars ( Figs 4H , 6H ) whereas males of the latter two species have the clava at least as long and sometimes distinctly longer than the combined length of the three apical funiculars ( Figs 1H , 5H ).

Figures

Figure 1. Anastatus fulloi A-E female: A dorsal habitus (13) B lateral habitus (12) C dorsal mesosoma (13) D lateral mesosoma (12) E fore wing (14). F-H male: F lateral habitus (22) G antenna (32) H clava and apical three funiculars (32) (three lower bars indicate length of clava compared to combined length of apical funiculars). Abbreviations: clv = clava, flx = flagellomere number.

Figure 2. Anastatus gansuensis, female A dorsal habitus (9) B lateral habitus (7) C head in frontal view (10) D, same in dorsal view (9) E mesosoma in dorsal view (9) F same in lateral view (7) G antenna (10) H pedicel and basal three funiculars (10) I clava and apical three funiculars (10). Abbreviations: clv = clava, flx = flagellomere number; pdl = pedicel

Figure 3. Anastatus spp., female A-E A. gansuensis: A fore wing (8) B basal half of fore wing (29) C enlargement of medial part of wing disc (8) D gaster in dorsal view (9) E mesotarsus and apex of mesotibia, in anterior view (7). F, G A. fulloi, mesotarsus and apex of mesotibia (12): F in anterior view G in posterodorsal view. Abbreviations: Gtx = gastral tergite number, syn = syntergum.

Figure 4. Anastatus gansuensis, male A dorsal habitus (17) B lateral habitus (16) C head in frontal view (19) D mesosoma in lateral view (16) E propodeum (17) F fore wing (17) G antenna (18) H pedicel and basal three funiculars (18) (three lower bars indicate length of clava compared to combined length of apical funiculars). Abbreviations: clv = clava, flx = flagellomere number.

Figure 5. Anastatus japonicus A-E female: A dorsal habitus (6) B lateral habitus (4) C mesosoma in dorsal view (6) D same in lateral view (4) E fore wing (5). F-H male: F lateral habitus (25) G antenna (25) H clava and apical three funiculars (25) (three lower bars indicate length of clava compared to combined length of apical funiculars). Abbreviations: clv = clava, flx = flagellomere number.

Figure 6. Anastatus meilingensis A-E female (2): A dorsal habitus B lateral habitus C dorsal mesosoma D lateral mesosoma E fore wing, dorsal view. F-H male (19): F lateral habitus G antenna H clava and apical three funiculars (three lower bars indicate length of clava compared to combined length of apical funiculars). Abbreviations: cbr = remnant of hyaline cross band, clv = clava, flx = flagellomere number.